At a normal room temperature of about 21 degrees C with light clothing, which mechanism accounts for the largest proportion of heat loss from the body?

• A Evaporation of sweat
• B Radiation ✓
• C Conduction to air
• D Convection by air currents

Explanation

In a temperate environment, radiation transfers roughly 60 percent of total body heat loss through infrared emission from skin to surrounding objects, without requiring direct contact. Evaporation becomes dominant only when ambient temperature approaches or exceeds skin temperature, since then radiation, conduction and convection can no longer dissipate heat. Conduction to still air is a minor route.

Reference: Guyton and Hall Textbook of Medical Physiology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.